KR20060049904A - Lighting apparatus and liquid crystal display apparatus - Google Patents

Abstract

The liquid crystal display device 11 includes a liquid crystal panel 12 and an illumination device 13 arranged on the rear side of the liquid crystal panel. The lighting device has an organic EL device 27 which is a light source. The organic EL device includes a pair of electrodes 24 and 25 and an organic layer 26 provided between the electrodes for emitting light when an electric field is applied to the organic layer. The emission spectrum of the organic EL device has peaks in each of the red, green, blue, and cyan wavelength regions. Therefore, the color of the printed matter of the liquid crystal display device is accurately reproduced.

Description

LIGHTING APPARATUS AND LIQUID CRYSTAL DISPLAY APPARATUS}

1A is a schematic diagram of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 1B is a schematic partial cross-sectional view of the LCD panel of FIG. 1A.

FIG. 1C is a schematic partial cross-sectional view of the lighting apparatus of the liquid crystal display of FIG.

FIG. 2 is a graph showing a spectrum emitted by the illuminating device of FIG. 1c (shown in solid line) and showing light transport characteristics (shown in broken lines) of the color filter used in the liquid crystal panel of FIG. .

3 is an x-y chromaticity diagram showing a relationship between red light, green light, blue light, and cyan light.

4 is a schematic view of a print shown as illuminated by another roughing device in a modified embodiment of the present invention.

5 is a schematic partial cross-sectional view of a lighting apparatus according to another modified embodiment of the present invention.

Fig. 6A is a graph showing the emission spectrum of the conventional white EL device.

6B is an x-y chromaticity diagram showing a relationship between red light, green light, and blue light.

Explanation of symbols on the main parts of the drawings

11. Liquid Crystal Display 13. Lighting

24. First electrode 25. Second electrode

26. Organic Layer 27. Organic EL Device

31a. Red light emitting portion 31b. Green light emitting part

31c. Blue light emitting portion 31d. Cyan Light Emitting Part

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination device and a liquid crystal display device, and more particularly, to an illumination device including an electroluminescent device (EL element) that emits white light as a light source.

In general, color displays such as television receivers and personal computer monitors use three primary colors of red (R), green (G), and blue (B), and are called a color mixing method called additive color mixing method. By forming a color image. Each pixel of the current general color display is composed of red, green, and blue sub-pixels. Light from a white light source is transmitted through red, green, and blue color filters to obtain three primary colors.

As the white light source, a fluorescent lamp or a white light emitting diode (white LED) is mainly used. As for the fluorescent lamp (three-wavelength tube), most of the luminescence intensity is distributed in three wavelength regions corresponding to red, green, and blue. White LEDs include a blue conversion type in which blue light is emitted and passes through a filter, which is converted into orange light, thereby producing a similar white light to blue and orange. White LEDs also include types in which the luminous intensity is defined for each central wavelength region of red, green and blue.

It has been proposed to use an organic EL element of white light emission as a backlight of a liquid crystal display device (see, for example, Japanese Patent Laid-Open No. 2002-229021). More specifically, the organic EL element emits three primary colors of red, green, and blue, or emits complementary colors such as blue and yellow to generate white light.

As shown in Fig. 6A, the emission spectra of LEDs or organic EL devices that emit three primary colors by white light using light correspond to red (about 620 nm), green (about 530 nm), and blue (about 455 nm). Has three peaks. As shown in the x-y chromaticity diagram of b of FIG. 6, the three primary colors each form a vertex of a triangle.

 In order to obtain more colors, a display device capable of displaying in a larger number of primary colors than the number of sub-pixels constituting each pixel has been proposed (see, for example, Japanese Patent Laid-Open No. 2004-138827). In the display device, for example, each pixel is formed of three sub-pixels. As the light source of the display device, six types of short wavelength blue (Bl), long wavelength blue (B2), short wavelength green (Gl), long wavelength green (G2), short wavelength red (Rl) and long wavelength red (R2) Emits light. The display period for displaying each image is divided into two periods, that is, a first period and a second period. The color of light emitted by the light source and the state of the subpixels of the first period are controlled differently from the subpixels of the second pixel. This makes it possible to display an image with a number of primary colors more than the number of sub-numbers.

Compared to the color gamut of liquid crystal color displays used in personal computers or digital still cameras, the color gamut of typical color prints, particularly inkjet type printers in widespread use, represents a large area corresponding to cyan. As a result, when an image is emitted by the liquid crystal color display, the printed image provides a different impression from the image appearing on the display.

Furthermore, when viewing a printed matter indoors such as a poster or painting, the printed matter or painting is illuminated by a conventional lighting device that emits white light with three primary colors of red (R), green (G), and blue (B). The primary color of cannot be reproduced sufficiently.

Accordingly, an object of the present invention is to provide a liquid crystal display device having an illumination device capable of reproducing the color of a color printed matter on a liquid crystal color display device, for example, accurately reproducing the reproduction of a print or a painting, and an illumination device. will be.

In order to achieve the above objects and other objects, the present invention provides an illumination device having an organic EL element as a light source. The organic EL element includes a pair of electrodes and an organic layer disposed between the electrodes for emitting light when an electric field is applied to the organic layer. The emission spectrum of the organic EL device has peaks in the red, green, blue and cyan wavelength regions.

Another aspect of the present invention is to provide a liquid crystal display device having a liquid crystal panel and a lighting device arranged on the rear side of the liquid crystal panel. The liquid crystal panel includes a plurality of pixels including a color filter and four subpixel sets. The color filter includes a plurality of filter part sets each including a red filter part, a green filter part, a blue filter part and a cyan filter part. Four subpixels in each set correspond to a red filter part, a green filter part, a blue filter part and a cyan filter part corresponding to an associated one of the filter part sets. Moreover, the lighting apparatus includes an organic EL element as a light source. The organic EL element includes a pair of electrodes and an organic layer disposed between the electrodes for emitting light when an electric field is applied to the organic layer. The emission spectrum of the organic EL device has peaks in the red, green, blue and cyan wavelength regions.

The invention and its objects and advantages can be better understood with reference to the following description of the preferred embodiments in conjunction with the accompanying drawings.

An embodiment of the present invention or a backlight of a full color liquid crystal display is described with reference to FIGS.

As shown in FIG. 1A, the liquid crystal display device 11 includes a transmissive liquid crystal panel 12 and an illumination device 13 provided as a backlight. The lighting device 13 is arranged at the rear side of the liquid crystal panel 12. That is, the illuminating device 13 is disposed on the surface of the liquid crystal panel 12 facing away from the display surface (display device screen) of the liquid crystal panel 12.

As shown in b of FIG. 1, the liquid crystal panel 12 is joined together by a seal material (not shown) and has a pair of transparent substrates 14 and 15 spaced at predetermined intervals. The liquid crystal 16 is sealed in the gap between the substrates 14 and 15. Substrates 14 and 15 are in the form of glass, for example. The substrate 14 is disposed on the side corresponding to the lighting device 13. On the surface of the substrate 14 facing the liquid crystal l6, a plurality of pixel electrodes 17 and thin film transistors (TFTs) 18 connected to the pixel electrodes 17 are provided. Each pixel electrode 17 is made of indium tin oxide (ITO). Four pixel electrodes 17 constitute a single pixel. Moreover, the polarizing plate 19 is formed in the board | substrate 14 on the surface of the board | substrate 14 which is another surface of the board | substrate 14 which faces the liquid crystal 16. As shown in FIG.

The color filter 16 is formed in the board | substrate 15 which faces the liquid crystal 16. FIG. On the color filter 20, a common transparent electrode 21 for pixels is formed. The transparent electrode 21 is also made of ITO. The color filter 20 includes a plurality of sets of filter portions, each set for transmitting red light, green light, blue light and cyan light, respectively, a red filter part 20a, a green filter part 20b, and a blue filter part 20c. ) And cyan filter portion 20d. The four pixel electrodes 17 forming the set are arranged on opposite sides of the corresponding filter portions 20a to 20d of the associated filter portion set. Adjacent portions of the filter portions 20a to 20d are separated from each other by the black matrix 22. The polarizing plate 23 is formed in the surface of the board | substrate 15 which is another surface of the board | substrate 15 which faces the liquid crystal 16. As shown in FIG.

That is, in the liquid crystal panel 12 of FIG. 1 b, each pixel includes four sub-pixels (four pixel electrodes 17), and each set of sub-pixels corresponds to a corresponding filter portion 20a of a set of associated filter portions. Except for being disposed on the opposite side of the to 20d), the configuration is basically the same as that of the known full color display liquid crystal panel.

As shown to c of FIG. 1, the illuminating device 13 has the organic electroluminescent element 27 as a light source in which the organic layer 26 is arrange | positioned between a pair of electrodes 24 and 25. As shown in FIG. The organic layer 26 emits light when an electric field is applied to the organic layer 26. More specifically, the organic EL element 27 is formed by sequentially stacking the first electrode 24, the organic layer 26, and the second electrode 25 on the substrate 28. The organic EL element 27 is covered with the protective film 29 so that the organic layer 26 is not adversely affected by moisture (water vapor) and oxygen.

In the illustrated embodiment, a transparent glass substrate is used as the substrate 28. The first electrode 24 is provided as an anode, and the second electrode 25 is provided as a cathode. The 1st electrode 24 is formed of ITO (indium tin oxide) used as a transparent electrode with a well-known organic electroluminescent element, and permeate | transmits light. The second electrode 25 is made of metal (for example, aluminum) to reflect light. The organic EL element 27 is formed of a so-called bottom emission type or of a type in which light emitted by the organic layer 26 emits the organic EL element 27 through the substrate 28. . The protective film 29 is formed of silicon nitride, for example.

The organic layer 26 is formed by laminating the hole transport layer 30, the light emitting layer 31, and the electron transport layer 32 on the first electrode 24 sequentially. The light emitting layer 31 is formed by a plurality of sets of light emitting portions each set consisting of a red light emitting portion 31a, a green light emitting portion 31b, a blue light emitting portion 31c and a cyan light emitting portion 31d. The red light emitting portion 31a, the green light emitting portion 31b, the blue light emitting portion 31c and the cyan light emitting portion 31d do not overlap with each other along the direction formed by the thickness of the organic layer 26. The light emitting portions 31a to 31d are arranged in a stripe pattern and extend in parallel with each other. The width of each light emitting portion 31a to 31d is substantially the same as the width corresponding to one of the filter layers 20a to 20d of the color filter 20. More specifically, the light emitted by the red light emitting portion 31a of the organic EL element 27 passes through the red filter portion 20a of the color filter 20 and is emitted by the green light emitting portion 31b. Light passes through the green filter portion 20b, light emitted by the blue light emitting portion 31c passes through the blue filter portion 20c, and light emitted by the cyan light emitting portion 31d passes through the cyan filter. Pass the part 20d.

In FIG. 1B and FIG. 1C, it is schematic which was shown for demonstrating the liquid crystal panel 12 and the illuminating device 13, The ratio of the magnitude | size of a component and thickness is for illustration and differs from an actual thing.

In the illustrated embodiment, the hole transport layer 30 is formed by vacuum deposition using a tetramer of triphenylamine (TPTE) having a methyl group at the meta position of terminal phenyl as the hole transport material. An electron transport layer 32, as the electron transporting material is formed by vacuum deposition using an aluminum tris (8-quinolinate play), called 8-CUNAULT metal complex, the so-called Alq ₃ of linoleate derivatives.

The red light emitting part 31a uses TPTE as a host and uses DCJTB (4-dicyanomethylene-6-cp-zoloridinostyryl-2-tert-butyl-4H-pyran) as a dopant (luminescent dye). It is formed by a vacuum vapor deposition method (co-deposition). The content of DCJTB is set to, for example, 0.5% by weight relative to TPTE. Since the dye formed by DCJTB emits red light, the red light emitting portion 31a emits red light.

The green light emitting part 31b is formed by vacuum evaporation (co-deposition) using Alq ₃ as a host and quinacridone (Qd) as a dopant (light emitting dye). Since the pigment | dye which consists of quinacridone Qd emits green light, the green light emitting part 31b emits green light.

The blue light emission part 31c sets the host as DPVBi (4, 4-bis (2,2-diphenyl-ethen-1 -yl) -biphenyl), and sets the dopant (luminescent dye) to BCzVBi (4, 4 '). bis (9-ethyl-3-carbazovinylenel) -1,1'-biphenyl) to form by vacuum evaporation (co-deposition). BCzVBi is contained in an amount of 5.0% by weight relative to DPVBi. Since the pigment | dye which consists of BCzVBi emits blue light, blue light emission part 31c emits blue light.

The cyan light emitting portion 31d is formed by a vacuum vapor deposition method using Balq ₂ (bis (2-methyl-8-quinolinolato) (p-phenylphenorato) aluminum (III)).

DCJTB and BAlq ₂ are represented by the following formulas.

Next, the operation of the liquid crystal display device 11 configured as described above will be described.

When power is supplied to the liquid crystal display device 11 to display an image on the display screen of the liquid crystal panel 12, a liquid crystal corresponding to a predetermined pixel related to the image to be displayed is indicated by an indication signal from a controller (not shown). A voltage is applied to l6). In this way, the pixel is switched to a display state or a state that can transmit light (incident light) from the illumination device 13. The amount of light transmitted through the liquid crystal 16 is controlled to correspond to the magnitude of the applied voltage.

In the lighting device 13, a voltage is applied to the first electrode 24 and the second electrode 25 via a control device. All the light emitting parts 31a to 31d of the organic EL element 27 emit light. More specifically, the red light emitting portion 31a emits red light, the green light emitting portion 31b emits green light, the blue light emitting portion 31c emits blue light, and the cyan light emitting portion 31d is cyan. It emits color light. Light from each of the light emitting portions 31a to 31d exits the roughening device 13 through the substrate 28 and enters the liquid crystal panel 12 through the substrate 14. As shown by the solid line in Fig. 2, the light emitted by the lighting device 13, i.e., the organic EL element 27, is sequentially blue, cyan, green and red, from the side of the short wavelength in its emission spectrum. Has a peak of light intensity corresponding to. In the illustrated embodiment, the wavelength of the peak in the blue wavelength region is about 455 nm, the wavelength of the peak in the cyan region is about 495 nm, the wavelength of the peak in the green wavelength region is about 530 nm, and the wavelength of the peak in the red wavelength region. Is about 620 nm.

When a voltage is applied to the pixel electrode 17, light of a light amount corresponding to the magnitude of the voltage is transmitted through the liquid crystal 16. Light passes through the filter portions 20a to 20d of the color filter 20 through the transparent electrode 21. An image formed by the light transported through the color filter 20 is visually recognized as an image displayed by the liquid crystal display device 11. Examples of the light transport characteristics of the respective filter portions 20a to 20d of the color filter 20 are shown by broken lines in FIG. 2.

When displaying a color image, the color of the image is adjusted as desired by mixing the three primary colors of red, green, and blue and cyan formed by corresponding pixels. In the illustrated embodiment, the amount of light exiting the illuminating device 13 is constant. Then, the amount of light transmitted through the portion of the color filter 20 corresponding to each pixel or the mixing ratio of red, green, blue, and cyan of each pixel is adjusted to correspond to the magnitude of the contact pressure applied to the pixel electrode 17. .

As shown by the x-y chromaticity diagram of FIG. 3, a peak corresponding to the coordinate of the peak in the red (R) wavelength region, a peak corresponding to the coordinate of the peak in the green (G) wavelength region, and a peak in the blue (B) wavelength region Each color reproduced in the three primary colors exists in the range of the triangle (RGB) formed by the vertex corresponding to the coordinate of. Therefore, most of the cyan-based color by cyan inks used in color printed matter exist outside of the triangle. Therefore, as a mixture of the light of three primary colors, the color of a color printed matter cannot be reproduced correctly.

However, in addition to the light emitting sections 31a to 31c corresponding to the three primary colors, the illuminating device 13 of the illustrated embodiment emits cyan light that emits cyan (C) light not included in the range corresponding to the triangle RGB. Light-emitting portion 31d. Therefore, the color portion formed by the three primary colors and cyan colors includes a peak corresponding to the coordinate of the peak in the red (R) wavelength region, a peak corresponding to the coordinate of the peak in the green (G) wavelength region, and a cyan (C) wavelength. It exists in the range of the rectangle (RGCB) of FIG. 3 formed by the vertex corresponding to the coordinate of the peak in the zone and the vertex corresponding to the coordinate of the peak in the blue (B) wavelength region. That is, the range of the triangle GCB formed outside the range of the triangle RGB is added to the color portion. Therefore, most of the cyan-based color produced by the cyan ink used in the color printed matter include the color portion reproduced by the light generated by the lighting device 13. As a result, the color of the color printed matter is accurately reproduced in the illustrated embodiment, as compared with the case where the color is adjusted using conventional three primary colors of light.

The illustrated embodiment has the following advantages.

(1) The illuminating device 13 used as the backlight of the liquid crystal display device 11 includes an organic EL element 27 in which the organic layer 26 is disposed between the electrodes 24 and 25 as a light emitting source. When an electric field is applied to the organic layer 26, the organic layer 26 emits light. The emission spectrum of the organic EL element 27 includes the peak of the cyan wavelength region in addition to the peak of the red, green, and blue wavelength regions. Therefore, the emission spectrum is different from the conventional backlight for color monitors having no cyan wavelength region, and the cyan color of the printed matter is also accurately reproduced on the screen of the liquid crystal panel 12. Furthermore, even when the image photographed by the digital still camera is printed, edited by the liquid crystal display device 11, and color is adjusted through the screen of the liquid crystal panel 12, the obtained image is obtained by the liquid crystal panel 12. It is not substantially different from the original image shown in.

(2) When the wavelength of the peak in the cyan wavelength region becomes too close to the wavelength of the peak in the green or blue wavelength region, good color expression (color adjustment) becomes difficult by mixing green light or blue light and cyan light. However, since the wavelength of the peak of the cyan wavelength region is in the range of 485 to 505 nm, color adjustment can be made with good color adjustment by mixing cyan with another color.

(3) In the organic layer 26, the light emitting parts 31a to 31d are arranged so as not to overlap each other along the direction formed by the thickness of the organic layer 26. This arrangement produces reliable light in which the organic EL element 27 as a light emitting source has an emission spectrum having peaks corresponding to red, green, blue and cyan.

The present invention is not limited to the illustrated embodiment, but may be implemented in the following modified forms.

The lighting device 13 can be used to illuminate the indoors. When the illuminating device 13 is used as a backlight of the liquid crystal display device 11, the width of each light emitting portion 31a to 31d should be substantially equal to the width of the sub pixel of the corresponding liquid crystal panel 12. Therefore, in order to reproduce an accurate image, the width of each light emitting layer 31a to 31d must be reproduced corresponding to the width of the sub pixel. However, when the illuminating device 13 is used for illuminating indoors, each light emitting layer (as long as the light emitted by the light emitting layers 31a to 31d cannot be visually transmitted as individual red light, green light, blue light and cyan light) 31a to 31d) width can be relatively large compared to the illustrated embodiment. When viewing the printed matter 33 or oil painting using the illuminator 13, the illuminator 13 emits light spectra having peaks in the red, green, blue and cyan wavelength regions. Therefore, even if the print 33 contains cyan-based colors adjusted by mixing cyan inks, the color of the print 33 can be accurately reproduced.

When the illuminating device 13 is used when viewing printed matter or oil painting, a diffuser such as a diffuser plate or diffuser can be formed on the light exit surface. In this case, the width of each light emitting portion 31a to 31d can be increased as compared with the case where no diffusion portion is formed. This promotes the formation of the light emitting portions 31a to 31d.

The light emitting layer 31 constituting the organic EL element 27 may be configured as in the illustrated embodiment in which the respective light emitting portions 31a to 31d are formed so as not to overlap each other along the direction formed by the thickness of the organic layer 26. There is no need. For example, as shown in FIG. 5, the red light emitting portion 31a, the blue light emitting portion 31c and the green light emitting portion 31b may be sequentially stacked on the hole transport layer 30 so as to overlap sequentially. In contrast, the cyan light emitting portion 31d can be laminated on the hole transport layer 30 without overlapping while holding the light emitting portions 31a to 31c. With respect to the structure in which the red light emitting portion 31a, the green light emitting portion 31b and the blue light emitting portion 31c are stacked in such a manner as to overlap, when the voltage is applied to the electrodes 24 and 25, the emission spectrum is red, green, Many organic materials are known in which white light having a peak in the blue wavelength region emits good light. Therefore, no problem arises even with this structure. Moreover, the order in which the light emitting parts 31a to 31c are arranged is not limited to the order shown in FIG.

If the cyan light emitting portions 31d can be stacked in such a manner as to overlap with other light emitting portions 31a to 31c without any problem with respect to the peak due to the emission spectrum, the light emitting portions 31a to 31d can overlap each other. . In this case, the widths of the light emitting portions 31a to 31d need not be substantially the same as the widths of the corresponding ones of the pixel electrodes 17. This makes it easy to form the light emitting portions 31a to 31d.

The organic materials forming the hole transporting layer 30 and the electron transporting layer 32 constituting the organic layer 26 are not limited to those described in the illustrated embodiment. Examples of the material for forming the hole transport layer include metal or nonmetal phthalocyanine, quinacridone compound such as copper phthalocyanine and tetra (t-butyl) copper phthalocyanine, 1,1-bis (4-Gp-tolylaminophenyl) cyclohexane, N, N'-diphenyl-N, N'-bis (3-methylphenyl) -1, 1'-biphenyl-4,4'-diamine and N, N'-di (1-naphthyl) -1, Low molecular weight materials such as aromatic amines such as N'-diphenyl-1,1'-biphenyl-4,4'-diamine, and high molecular materials such as polythiophene and polyaniline, and polythiophene oligomer materials, and other It can be selected from existing hole transport materials.

Materials for forming the electron transporting layer 32 are, for example, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, and 2,5-bis Oxadiazole derivatives such as (1 -naphthyl) -1,3,4-oxadiazole, and bis (10-hydroxybenzo [h] quinolinorato) beryllium complexes, and triazole compounds.

Similarly, the organic materials forming the light emitting portions 31a to 31c are not limited to the illustrated embodiment, but may be replaced with existing light emitting materials. As a material of the red light emission part 31a, TPTE can be used as a host and DCJT can be used as a dopant, for example. DCJT is formed by converting the tert-butyl group of DCJTB into a methyl group. The material of the green light emitting portion 31b may be, for example, Alq ₃ or benzoquinolinol beryllium complex (Bebq ₂ ). Optionally, the material of the green light emitting portion 31b has Alq ₃ as a host and 10-(2-benzothiazonyl) -2,3,6,7-tetrahydro-1,1,7,7-tetra Methyl-1H, 5h, lH- [1] benzopyrano [6, 7, 8-ij] quinolizine-11-one (called C545T) may be used as the dopant. C545T is a trade name of Eastman-Kodak Corporation. The blue light emitting part 31c may be, for example, a benzozole complex (Zn (oxz) ₂ ) of zinc.

The organic layer 26 does not necessarily need to consist of the triple layer or the hole transport layer 30, the light emitting layer 31, and the electron transport layer 32. For example, a hole injection layer may be formed between the first electrode 24 (anode) and the hole transport layer 30. Further, the hole injection layer can be formed between the electron transport layer 32 and the second electrode 25 (cathode). Alternatively, the hole injection layer can be disposed on one side of the light emitting layer 31, and the electron injection layer can be formed on the opposite side. In addition, the organic layer 26 may include a buffer layer or a hole block layer that can be used for a known organic EL layer. This layer can be formed of known materials by known methods. Moreover, depending on the material for forming the light emitting layer 31, the organic layer 26 can be simply formed by the light emitting layer 31.

The organic EL element 27 is not limited to the bottom emission, and the light emitted by the organic layer 26 is a so-called top emission type which emits the organic EL layer 27 from the opposite side to the substrate 28. Can be. In this case, the second electrode 25 is formed of a transparent electrode, and the first electrode 24 is not limited to the transparent electrode but may be an opaque electrode. In order to improve the electron injection efficiency from the cathode, the work function of the material forming the cathode is generally preferably 4.0 eV or less. However, the work function of ITO is 4.8 eV. Therefore, when the second electrode 25 is formed of ITO, the electron transport layer 32 is formed close to the light emitting layer 31 between the light emitting layer 31 and the second electrode 25, and the light emitting layer 31 and the second electrode are formed. It is preferable that an electron injection layer is formed between the 25 and close to the second electrode 25. In addition, since the material having the improved work function promotes the hole injection, the anode is preferably formed of this kind of material. ITO is preferable as the material of the anode, but the first anode 24 of the top emission organic EL element 27 need not be transparent, and may be formed of a metal having a small resistance to ITO. The work function (unit eV) of the metal is chromium 4.5, nickel 5.15, gold 5.1, palladium 5.55, copper 4.65, aluminum 4.28, magnesium 3.36. Therefore, when the first electrode 24 is made of metal, it is preferable that a hole injection layer is formed between the hole transport layer 30 and the first electrode 24.

When the organic EL element 27 is a bottom emission type, the second electrode 25 does not need to reflect light. However, when the second electrode 25 reflects light, the light emitted from the light emitting layer 31 to the second electrode 25 is reflected by the second electrode 25 and emitted from the first electrode 24. Therefore, compared with the case where the light reflected by the second electrode 25 is used, the amount of light emitted from the organic EL element 27 becomes considerably higher.

The material of the protective film 29 is not limited to silicon nitride, and any material may be used in which the organic layer 26 can be protected from external oxygen or moisture. Therefore, the protective film 29 may be formed of silicon oxide or diamond carbon, or may be formed of a polymer material. Furthermore, instead of the protective film 29, the glass cover or the metal cover may cover the portion of the organic EL element 27 in addition to the portion opposite to the substrate 28.

The shape of each pixel of the liquid crystal panel 12 is not limited to the structure in which four rectangular subpixels are arrange | positioned in parallel with each other. Optionally, for example, four subpixels can be divided into two pairs of subpixels arranged side by side. Subpixels are then arranged in such a way that one of the pair of subpixels is arranged on the opposite side of the other. Moreover, the shape of each subpixel is not limited to the quadrangle, but may be another shape including a triangle or a hexagon. In this case, the shape of each light emitting portion 31a to 31d must also be changed correspondingly.

The present examples and embodiments are not to be considered as illustrative and the invention is not to be limited to the details given herein, but may vary within the scope and identity of the appended claims.

According to the present invention, the color of a color printed matter can be reproduced on a liquid crystal color display device, and for example, a liquid crystal display device having an illuminating device and an illuminating device which accurately improves the reproduction accuracy of a printed matter or a painting can be provided.

Claims (10)

As a lighting apparatus having an organic EL element 27 as a light source, the organic EL element comprises a pair of electrodes 24 and 25 and an organic layer 26 disposed between the electrodes for emitting light when an electric field is applied to the organic layer. In the lighting device comprising: And an emission spectrum of the organic EL element has peaks in respective red, green, blue, and cyan wavelength regions. 2. An illuminating device according to claim 1, wherein the cyan wavelength region is in the range of 485 to 505 nm. The wavelength region of claim 1, wherein the cyan wavelength region is in an optical wavelength region having a chromaticity outside the triangle formed by each vertex corresponding to the coordinates of one of the peaks in the red, green, and blue wavelength regions in the x-y chromaticity diagram. Illuminating apparatus, characterized in that corresponding. The organic layer according to any one of claims 1 to 3, wherein the organic layer comprises a plurality of red light emitting portions 31a, green light emitting portions 31b, blue light emitting portions 31c, and cyan light emitting portions 31d, The red light, the green light, the blue light and the cyan light emitting portion is disposed so as not to overlap each other along the direction formed by the thickness of the organic layer. 4. The organic layer according to any one of claims 1 to 3, wherein the organic layer comprises a plurality of sets of light emitting portions, each set of a red light emitting portion 31a, a green light emitting portion 31b, a blue light emitting portion 31c, and cyan. A color light emitting part 31d, wherein each set of red light, green light, and blue light light emitting parts is stacked along the direction formed by the thickness of the organic layer, and disposed so as not to overlap with the cyan light emitting part along the direction formed by the thickness of the organic layer. Illumination apparatus, characterized in that. The illuminating device according to any one of claims 1 to 3, wherein the illuminating device is used as a backlight of the liquid crystal display device. A liquid crystal panel (12), the liquid crystal panel (12) including a color filter (20), the plurality of pixels each comprising four sets of sub-pixels (17), and the color filter comprising a plurality of filter portions sets Each set includes a red filter portion 20a, a green filter portion 20b, a blue filter portion 20c and a cyan filter portion 20d, each of the four sub-pixels being associated with a set of associated filter portions. Corresponds to the red, green, blue, and cyan colors of The liquid crystal display device according to any one of claims 1 to 3, wherein the illumination device is arranged on the rear side of the liquid crystal panel. 8. The organic layer according to claim 7, wherein the organic layer comprises a plurality of sets of light emitters, each set comprising a red light emitter 31a, a green light emitter 31b, a blue light emitter 31c, and a cyan light emitter 31d. A red light, green light, blue light, and cyan light emitting part of each light emitting part set respectively corresponding to the red, green, blue, and cyan filter parts of the associated filter part set, and the red light, green light, blue light, and cyan light light emitting part of the organic layer. And a liquid crystal display device disposed so as not to overlap each other along the direction formed by the thickness. 9. The red light emitting portion, the green light emitting portion, the blue light emitting portion, and the cyan light emitting portion are arranged in a stripe pattern and extend in parallel with each other, and the width of each light emitting portion is substantially red, green, blue, and cyan filter portion. The liquid crystal display device, characterized in that the same as the width corresponding to. 8. The organic layer according to claim 7, wherein the organic layer includes a plurality of sets of light emitting portions, each set comprising a red light emitting portion 31a, a green light emitting portion 31b, a blue light emitting portion 31c, and a cyan light emitting portion 31d. The red light, green light, blue light and cyan light light emitting part of each light emitting part set correspond to the red, green, blue and cyan filter parts of the associated filter part set, respectively, and the red light, green light and blue light light emitting part of each light emitting part set The liquid crystal display device, wherein the liquid crystal display is stacked in a direction formed by the thickness of the light emitting device, and is disposed so as not to overlap with the cyan light emitting part of the light emitting part set in the direction formed by the thickness of the organic layer.

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